It seems they've also developed the ability to "shed" their stalk-like appendages.

"It's the lizard's tail strategy," said Baumiller, who is also a curator in the UM Museum of Paleontology. "The sea lily just leaves the stalk end behind. The sea urchin is preoccupied going after that, and the sea lily crawls away." And the speed at which they move---three to four centimeters per second---suggests that "in a race with a sea urchin, the sea lily would probably win."

Kevin: Imagine that I let you borrow $50, but in exchange for my generosity, you promise to pay me back the $50 with an extra $10 in interest. To make sure you pay me back, I take your Charizard Pokémon card as collateral.

Olivia: Kevin, I don't play Pokémon anymore.

Kevin: I'm getting to that. Let's say that the Charizard is worth $50, so in case you decide to not return my money, at least I'll have something that's worth what I loaned out.

Olivia: Okay.

Kevin: But one day, people realize that Pokémon is stupid and everyone decides that the cards are overvalued. That's right -- everybody turned twelve on the same day! Now your Charizard is only worth, say, $25.

The only thing that's missing is the part of the explanation where the parents swoop in and pay Kevin full value for that Pokémon card, which allows him to keep lending money in exchange for cardboard rectangles.